We can also access the SBB from level 15 on (careful not to outlevel your contacts though if you do it then!), plus Cathedral of Pain and all the iTrials are open to us if they start in Pocket D or Praetoria. Via Ouro you can get The Emperor's Sword arc (as you mentioned above), you just have to go to Night Ward in person to get in. It has to be via Ouro though, because she won't talk to you directly, which is crazy! And you can also do Cole's personal story.
And as @Six-Sixsaid above, base crystal will allow you to do whatever you missed along the way. And there's organizing a Seed of Hamidon raid in First Ward, that's good for some decent XP too.
And yes, there's AE, but there's VERY little Praetorian based material storywise there. I'm attempting to fix that though! Just published "Bridge of Forever", arc id 36642. Set prior to the War, level 20 cap so a pre crosser can play it. More on the way!